Re: Default value for a record component

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Mon, 23 Jul 2007 12:17:46 -0700, Maciej Sobczak wrote:

> On 22 Lip, 23:44, Robert A Duff <bobd...@shell01.TheWorld.com> wrote:
> 
>> If you want to hide both
> 
> The point is I don't.
> 
> The C++ version:
> 
> class T
> {
> public:
>    T() : V(getDefault()) {}
> 
>    int V;
> 
> private:
>    static int getDefault();
> };
> 
> (or even I can hide getDefault in the implementation file completely,
> without even mentioning it in the class definition)
> 
>>> Ada needs real constructors, not just initial values.
>
>> I don't get it.  Please explain.
> 
> The visibility of a component and the mechanics of computing its
> initial value are orthogonal and should not depend on one another. I
> can have completely separate reasons to expose or hide either of them.

(see Jeff Carter's post)

You are barking at a wrong tree. It looks more like an abstract member
interface. So that you could declare that there is an Integer component V
in T, while hiding all stuff about its initialization / finalization /
reading / writing. Parent's construction is only a part of the problem.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de